Diagnóstico silvicultural de floresta secundária transformada na Amazônia Central

Abstract

In the Amazon, it is estimated that there are more than 78 million hectares of secondary forests with great economic potential. Secondary forests are important for the ecological balance of the environment by assisting in the cycling of nutrients, conserving water and soil, and providing raw material for wood and non-wood products. For the management of a forest, some silvicultural treatments can be applied and are determined from the silvicultural diagnosis, which is a tool capable of projecting the possibilities of future management, based on existing individuals. In this sense, this work aims to diagnose the silvicultural potential of a secondary forest enriched and improved with forest species of socioeconomic importance. The experimental area is located on the AM-363 highway that connects Itacoatiara and Silves, and is a secondary forest that is currently 23 years old and has a size of 3.0 hectares. In 2014, the following were carried out: a forest inventory where 308 existing species were surveyed; the removal of some non-commercial trees; and enrichment planting was carried out with the forest species Bertholletia excelsa, Carapa guianensis and Euterpe oleracea. To carry out the silvicultural diagnosis of the area, all the trees were measured and classified according to the characteristics to be evaluated in the field sheet that contained information on: DBH, quality of the stem and crown, crown shape, lianas infestation. In addition, the growth of species was compared in an interval of 8 years, from the first survey carried out (2014) and the year of the present research (2022). It was verified that the species of this stand had a good growth rate in diameter in relation to the secondary forests that are not applied nor a type of silvicultural treatment. They also showed a lower rate of lianas infestation and higher rates of emergent individuals or with direct overhead lighting and perfect canopy shapes and/or good shape, factors correlated with growth in diameter of forest species. The planting of Carapa guianensis showed good growth in diameter, but with intense bifurcation and branching, and much lower quality of the stem, not being interesting from the point of view of wood production, but in terms of fruit production.